Is cryoablation a valid option for renal cell carcinomas in direct contact with critical organs?

PURPOSE

This study aimed to assess the outcomes of percutaneous cryoablation (PCA) for renal cell carcinomas (RCCs) contacting critical organs without intervening fat tissue.

MATERIAL AND METHODS

Twenty-three patients with 24 RCCs (mean size, 28.8 mm) contacting critical organs on preprocedural images were included. The organ displacement techniques, technical success, efficacy, and adverse events per Clavien-Dindo classification were retrospectively reviewed.

RESULTS

The organs contacting the RCCs included the colon (n = 16), pancreas (n = 3), duodenum (n = 3), small intestine (n = 1), and stomach (n = 1). In all procedures, hydrodissection was conducted, and probe traction was additionally utilized in one to displace organs. Two procedures were terminated with an insufficient ice-ball margin (<6 mm) due to recurring proximity of the colon or thermal sink effect by renal hilar vessels, yielding a technical success rate of 91.6% (22/24). No severe adverse events were noted. All patients were alive without any metastases during a median follow-up of 34.4 months. The primary and secondary technical efficacy rates were 91.6% (22/24) and 95.8% (23/24) of tumors, respectively.

CONCLUSION

PCA can be a valid option for RCCs contacting critical organs with a good safety profile and sufficient technical efficacy.

Ablation of Kidney Tumors in Patients with Substantial Kidney Impairment: Current Status

PURPOSE OF REVIEW

To review the current status of kidney tumor ablation in patients with substantial kidney impairment.

RECENT FINDINGS

Few reports of kidney tumor ablation in such patients have recently been published. The reported prevalence of patients with stage 4 or 5 chronic kidney disease (CKD) among patients undergoing ablation is 2.0%-10%. In patients with stage 4 or 5 CKD, local tumor control rates were 88%-100%. The effect of ablation on CKD stage is unclear, and the observed deteriorations in kidney function are consistent with both the effect of cryoablation and the natural course of advanced CKD. According to guidelines, active surveillance may be selected. The goals of treatment are complete tumor removal and maintenance of kidney function, both of which can be met by ablation. Given the limited treatment options, ablation may play a pivotal role in the management of patients with advanced CKD.

Successful treatment for life threatening recurrent non-traumatic rectus sheath hematoma in a case with microscopic polyangiitis with rapidly progressive glomerulonephritis

A 68-year-old woman was admitted to our hospital because of a rapid progression of renal dysfunction with positive myeloperoxidase antineutrophil cytoplasmic antibody and was diagnosed with rapidly progressive glomerulonephritis associated with microscopic polyangiitis (MPA). Severe right rectus sheath hematoma (RSH) bleeding from the inferior epigastric artery developed after starting hemodialysis, which required 4 transarterial embolizations due to recurrent bleeding. After additional treatment with methylprednisolone pulse therapy and rituximab, no rebleeding occurred. Although the giant hematoma reached the pelvis, it shrank spontaneously without any intervention. Nontraumatic RSH should therefore be considered when treating patients with multiple risk factors.

Photon-Counting Detector CT: Potential for 75% Reduction in Contrast Medium Amount: A Phantom Study

This study aimed to evaluate the potential reduction in contrast medium utilization using photon-counting detector computed tomography (PCD-CT). One PCD-CT scan (CT1) and three conventional (non-PCD-CT) CT scans (CT2-CT4) were performed using a multi-energy CT phantom that contained eight rods with different iodine concentrations (0.2, 0.5, 1, 2, 5, 10, 15, and 20 mg/ml). The CT values of the seven groups (CT1 for 40, 50, 60, and 70 keV; and CT2-4) were measured. Noise and contrast-to-noise ratio (CNR) were assessed for the eight rods at various iodine concentrations. CT2 and CT1 (40 keV) respectively required 20 mg/ml and 5 mg/ml of iodine, indicating that a comparable contrast effect could be obtained with approximately one-fourth of the contrast medium amount. The standard deviation values increased at lower energy levels irrespective of the iodine concentration. The CNR exhibited a decreasing trend with lower iodine concentrations, while it remained relatively stable across all iodine levels (40-70 keV). This study demonstrated that virtual monochromatic 40 keV images offer a similar contrast effect with a reduced contrast medium amount when compared to conventional CT systems at 120 kV.

Time course of complications after small renal mass biopsy: evaluation of initial follow-up images

PURPOSE

To retrospectively assess the time course of complications after image-guided small renal mass biopsy using initial follow-up imaging.

MATERIALS AND METHODS

A total of 190 masses (mean, 2.1 ± 0.70 cm; range, 0.6-3.8 cm) were assessed using initial computed tomography (43 non-enhanced and 141 enhanced) or magnetic resonance imaging (five non-enhanced and one enhanced) after biopsy. Initial follow-up imaging was classified into two groups (i.e., with or without hematoma) and various factors were compared.

RESULTS

The masses were histologically diagnosed in all patients except one. Post-procedural complications included 129 Grade I hematomas, 1 Grade I hemothorax, 9 Grade II hematomas, and 1 Grade IIIa pneumothorax. Residual 28 Grade I and 6 Grade II hematomas and 8 new complications (6 small hematomas, 1 pseudoaneurysm, and 1 arteriovenous fistula) were observed on the initial follow-up imaging obtained at a median of 21 days (3-90 days) after the biopsy. On the initial follow-up imaging, the groups with and without hematoma differed significantly in the following factors: age (P = 0.04), size (P = 0.02), guided images (P < 0.01), hematoma at the end of the procedure (P < 0.01), and days after biopsy (P < 0.01). Although three masses exhibited > 25% shrinkage, no significant change was observed in mass diameter on initial follow-up imaging (mean, 2.1 ± 0.71 cm; P = 0.90).

CONCLUSION

Initial follow-up imaging after a biopsy revealed improvements in most of the complications, a few new complications, and an unchanged mass diameter.

Prospective evaluation of core number of biopsy for renal tumor: are multiple cores preferable?

PURPOSE

This single-center, single-arm, prospective, open-label study was conducted to evaluate the optimal number of cores (single or multiple) in renal tumor biopsy.

MATERIALS AND METHODS

Forty-four biopsies of 44 tumors (mean diameter, 2.7 ± 1.0 cm; range, 1.6-5.0 cm) were included. Biopsy was performed under ultrasound or computed tomography fluoroscopy guidance using an 18-gauge cutting needle and the co-axial method. Two or more specimens were obtained, which were divided into first and subsequent specimens. "First specimen" and "all specimens" were histologically evaluated (i.e., appropriateness of specimen, histological diagnosis, subtype, and Fuhrman grade of renal cell carcinoma [RCC]) blindly and independently by two board-certified pathologists.

RESULTS

Multiple specimens were successfully and safely obtained in all the biopsies. All tumors were histologically diagnosed; 40 malignancies included 39 RCCs and 1 solitary fibrous tumor, and 4 benign lesions included 2 angiomyolipomas, 1 oncocytoma, and 1 capillary hemangioma. In all RCCs, the subtype could be determined (32 clear cell RCCs, 4 chromophobe RCCs, and 3 papillary RCCs), and the Furman grade was determined in 38 RCCs. When only the first specimen was evaluated, 22.7% of the specimens were inappropriate for diagnosis, and 34 (77.3%) were histologically diagnosed. The diagnostic yield was significantly lower than that of all specimens (P = 0.0044). Univariate analysis revealed that smaller lesions were a significant predictor of diagnostic failure (P = 0.020).

CONCLUSION

Biopsy with multiple cores significantly improved diagnostic yield. Thus, operators should obtain multiple cores during renal tumor biopsy.

Depiction rate of feeding arteries of renal cell carcinoma on four-dimensional computed tomography angiography

PURPOSE

To retrospectively evaluate the depiction rate of feeding arteries in biopsy-proven clear cell renal cell carcinoma (CCRCC) on four-dimensional computed tomography angiography (4D-CTA) images.

MATERIALS AND METHODS

This study included 22 patients with 22 CCRCC and 30 feeding arteries treated with transcatheter renal artery embolization. The depiction rate of the feeding arteries on preprocedural 4D-CTA was evaluated. Images were acquired by 320-row multi-detector computed tomography (CT) 15‒36 s after starting to inject a contrast agent (600 mg/kg iodine) intravenously into patients at 2.1 s intervals (11 phases). Two board-certified radiologists retrospectively assessed the feeder depiction rate in all 11 phases with reference to the procedural images as the gold standard. Discrepancies were resolved by consultation with a third radiologist.

RESULTS

Among the feeders, 11 (36.7%) were segmental or lobar, and 19 (63.3%) were interlobar or arcuate arteries. The feeder depiction rate was the highest (25 [83.3%] of 30) in the 5th phase (delay, 23.4 s) where the gap in contrast enhancement between the renal artery and cortex was the largest. This was followed by the 6th (23 [76.7%] of 30), 4th (22 [73.3%] of 30]), and 7th (21 [70.0%] of 30) phases. The overall rate of depicting feeding arteries in the 11 phases of 4D-CTA was 28 (93.3%) of 30.

CONCLUSIONS

The depiction rate of CCRCC feeding arteries including lobar or smaller artery branches by 4D-CTA was favorable. The feeding arteries were optimally visualized during the phase with the largest contrast gap between the renal artery and cortex.

Robotic systems in interventional oncology: a narrative review of the current status

Interventional oncology offers minimally invasive treatments for malignant tumors for curative and palliative purposes based on the percutaneous insertion of needles or catheters into the target location under image guidance. Robotic systems have been gaining increasing attention as tools that provide potential advantages for image-guided interventions. Among the robotic systems developed for intervention, those relevant to the oncology field are mainly those for guiding or driving the needles in non-vascular interventional procedures such as biopsy and tumor ablation. Needle-guiding robots support planning the needle path and align the needle robotically according to the planned trajectory, which is combined with subsequent manual needle insertion by the physician through the needle guide. Needle-driving robots can advance the needle robotically after determining its orientation. Although a wide variety of robotic systems have been developed, only a limited number of these systems have reached the clinical phase or commercialization thus far. The results of previous studies suggest that such interventional robots have the potential to increase the accuracy of needle placement, facilitate out-of-plane needle insertion, decrease the learning curve, and reduce radiation exposure. On the other hand, increased complexity and costs may be a concern when using robotic systems compared with conventional manual procedures. Further data should be collected to comprehensively assess the value of robotic systems in interventional oncology.

Arterial embolization via retrograde approach using steerable microcatheter and triaxial system

We report a case of postoperative pseudoaneurysm, successfully treated with selective arterial embolization, using a steerable microcatheter and triaxial system via retrograde approach. A pseudoaneurysm was detected in the dorsal pancreatic artery, a severely narrow and steeply inverted branch of the superior mesenteric artery, making microcatheter insertion via the antegrade approach challenging. However, a steerable microcatheter was advanced beyond the orifice and the tip was reversed, changing the route to retrograde allowing for easy insertion of the microguidewire. Subsequently, a small microcatheter was advanced beyond the pseudoaneurysm into the dorsal pancreatic artery, and arterial embolization was successfully completed without complications.

Automated Feeder-Detection Software for Renal Cell Carcinoma Embolization: A Retrospective Evaluation of Detection Rate Using Transarterial Time-Resolved Computed Tomography Angiography

PURPOSE

To evaluate the detection rate of feeding arteries in renal cell carcinoma with automated feeder-detection software and determine the optimal imaging phase for accurate feeder detection with transarterial time-resolved computed tomography angiography.

MATERIALS AND METHODS

The performance of automated feeder-detection software was retrospectively evaluated using transarterial renal time-resolved computed tomography angiography images of 15 renal cell carcinomas (mean size, 22.1 mm); the images were obtained via the renal artery using a hybrid angio-CT system with 320-row computed tomography, across nine phases with 0.5-s intervals over a contrast delay time of 1.0-5.0 s. Automated feeder-detection software was applied to each phase in all tumors (135 image series in total). The feeder-detection rate (i.e., sensitivity) in each phase was evaluated, and the number of false feeders demonstrated by the software was counted for each tumor.

RESULTS

A total of 22 feeders were identified. The feeder-detection rate was the highest (95.5% [21/22]) at delay times of 1.5 s and 2.0 s and lower in later phases. At delay times of 1.0 s and 1.5 s, the software demonstrated no or only a few (≤ 3) false feeders in 93.3% (14/15) of the tumors. In later phases, however, many (≥ 4) false feeders were observed in > 50% of tumors.

CONCLUSION

The automated feeder-detection software showed a favorable feeder-detection rate and may be useful in transarterial embolization for renal cell carcinoma. The optimal delay time to avoid the demonstration of false feeders and achieve a high detection accuracy was 1.5 s.

LEVEL OF EVIDENCE IV

Case Series.

Omental Abscess after Laparoscopic Proximal Gastrectomy Successfully Treated with Percutaneous Drainage

We report the case details of a 65-year-old Japanese man with an omental abscess that was discovered 43 days after he underwent a laparoscopic proximal gastrectomy for gastric cancer. His chief complaint was mild abdominal pain that had persisted for several days. The abscess was diagnosed as a rare postoperative complication. We hesitated to perform a reoperation given the invasiveness of general anesthesia and surgery, plus the possibility of postoperative adhesions and because the patient's general condition was stable and he had only mild abdominal pain. Percutaneous drainage using a 10.2-F catheter was performed with the patient under conscious sedation and computed tomography-fluoroscopy guidance, with no complications. After the procedure, the size of the abscess cavity was remarkably reduced, and 23 days later the catheter was withdrawn.

Renal cryoablation combined with prior transcatheter arterial embolization in non-dialysis patients with stage 4 or 5 chronic kidney disease: a retrospective study

PURPOSE

To retrospectively evaluate cryoablation combined with prior transcatheter arterial embolization (TAE) for renal cell carcinoma (RCC) in non-dialysis patients with stage 4 or 5 chronic kidney disease (CKD).

MATERIALS AND METHODS

Patients with stage 4 or 5 CKD undergoing TAE and cryoablation for RCC between May 2012 and October 2021 were included. TAE was selectively performed using iodized oil with absolute ethanol or gelatin sponge 1-14 days before cryoablation. Local efficacy, safety, and changes in renal function were evaluated.

RESULTS

Nine patients (seven men and two women; median age, 64 years; range 52-88 years) with nine RCCs (mean diameter, 3.0 ± 1.0 cm; range 1.7-4.7 cm) were included. The mean pre-treatment estimated glomerular filtration rate (eGFR) was 24.2 ± 5.6 ml/min/1.73 m2 (range 10.4-29.2 ml/min/1.73 m2). The mean amount of contrast medium used in TAE was 58 ± 29 ml (range 40-128 ml). Except in one patient (grade 3 pyelonephritis), no grade ≥ 3 complications occurred. During the follow-up period (median, 18 months; range 7-54 months), no local tumor progression occurred. In two patients with pre-treatment eGFR of < 20 ml/min/1.73 m2, hemodialysis was initiated at 3 and 19 months after cryoablation. At their last follow-up, the remaining seven patients showed a decrease of 6.2 ± 5.3 ml/min/1.73 m2 (range 0.7-17.2 ml/min/1.73 m2) in their eGFR.

CONCLUSION

Cryoablation combined with TAE for RCC in non-dialysis patients with stage 4 or 5 CKD was effective and safe, with an acceptable impact on renal function.

Image-Guided Ablation Therapies for Extrahepatic Metastases from Hepatocellular Carcinoma: A Review

The most common sites of extrahepatic metastases from hepatocellular carcinoma (HCC) are the lungs, intra-abdominal lymph nodes, bones, and adrenal glands, in that order. Although systemic therapies are a common treatment for patients with extrahepatic metastases, local ablative therapies for the extrahepatic metastatic lesions can be performed in selected patients. In this article, the literature on image-guided thermal ablation for metastasis to each organ was reviewed to summarize the current evidence. Radiofrequency ablation was the most commonly evaluated technique, and microwave ablation, cryoablation, and percutaneous ethanol injection were also utilized. The local control rate of thermal ablation therapy was relatively favorable, at approximately 70-90% in various organs. The survival outcomes varied among the studies, and several studies reported that the absence of viable intrahepatic lesions was associated with improved survival rates. Since only retrospective data from relatively small studies has been available thus far, more robust studies with prospective designs and larger cohorts are desired to prove the usefulness of thermal ablation for extrahepatic metastases from HCC.

Complications of Percutaneous Cryoablation for Renal Tumors and Methods for Avoiding Them

Percutaneous cryoablation of renal tumors is widely used because of its high efficacy and safety. This high safety can be attributed, at least in part, to the visibility of the ablated area as an "ice ball". This therapy has fewer complications (incidence, 0-7.2%) and is less invasive than surgery. Minor bleeding is inevitable in most kidney-related procedures, and indeed the most common complication of this therapy is bleeding (hematoma and hematuria). However, patients require treatment such as transfusion or transarterial embolization in only 0-4% of bleeding cases. Various other complications such as ureteral or collecting system injury, bowel injury, nerve injury, skin injury, infection, pneumothorax, and tract seeding also occur, but they are usually minor and asymptomatic. However, operators should know and avoid the various complications associated with this therapy. This study aimed to summarize the complications of percutaneous cryoablation for renal tumors and provide some techniques for achieving safe procedures.

Navicular Bone Fracture after Radiofrequency Ablation in a Patient with Osteoid Osteoma

Osteoid osteoma (OO) is a benign bone tumor that presents with nocturnal pain. Computed tomography (CT)- guided radiofrequency ablation (RFA) has been widely performed for OO, and major adverse events post-RFA are rare. We report a case of OO in the left navicular bone of a 15-year-old male. He underwent RFA for OO, and the pain improved temporarily. At the 1-month follow-up, the patient complained of left foot pain, and a CT examination revealed a fracture of the ablated navicular bone. Fractures are rare but must be taken into account after bone RFA.

A single-center, single-arm, prospective, open-label trial to evaluate the efficacy and safety of percutaneous sclerotherapy with polidocanol for painful venous malformations (SCIRO-2001): study protocol

This single-center, single-arm, prospective open-label trial is being conducted to evaluate the short-term efficacy and safety of percutaneous sclerotherapy with polidocanol foam for painful venous malformations. This study will include patients who were clinically diagnosed with venous malformation by using ultrasound and/or magnetic resonance imaging, and whose pain persisted even after treatment with medications. Written informed consent for sclerotherapy will be obtained from all patients. The institutional review board approved this prospective study protocol. The primary endpoint is pain relief at three months after sclerotherapy. Local pain related to venous malformation will be evaluated using a numeric rating scale. Patient recruitment commenced in December of 2020. Enrolment of 13 patients is planned over a 3-year recruitment period. Herein, we describe the details of the clinical trial protocol.

Evidence on percutaneous radiofrequency and microwave ablation for liver metastases over the last decade

Purpose

This review aimed to summarize the treatment outcomes of percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) for metastatic liver tumors based on the findings of published studies over the last decade.

Materials and methods

Literature describing the survival outcomes of ablation therapy for liver metastases was explored using the PubMed database on April 26, 2022, and articles published in 2012 or later were selected. The included studies met the following criteria: (i) English literature, (ii) original clinical studies, and (iii) literature describing overall survival (OS) of thermal ablation for metastatic liver tumors. All case reports and cohort studies with fewer than 20 patients and those that evaluated ablation for palliative purposes were excluded.

Results

RFA was the most commonly used method for ablation, while MWA was used in several recent studies. RFA and MWA for liver metastases from various primary tumors have been reported; however, majority of the studies focused on colorectal cancer. The local control rate by RFA and MWA varied widely among the studies, ranging approximately 50–90%. Five-year survival rates of 20–60% have been reported following ablation for colorectal liver metastases by a number of studies, and several reports of 10-year survival rates were also noted.

Conclusion

Comparative studies of local therapies for colorectal liver metastases demonstrated that RFA provides comparable survival outcomes to surgical metastasectomy and stereotactic body radiation therapy.

Up-to-date evidence on image-guided thermal ablation for metastatic lung tumors: a review

The aim of this review was to summarize the latest evidence on image-guided thermal ablation therapies for lung metastases. PubMed was used to search for relevant articles that reported the oncological outcomes of thermal ablation for metastatic lung tumors, and those published in 2010 or later were selected for review. Ablative therapies were applied for lung metastases from various types of primary tumors, but most commonly colorectal ones. Radiofrequency ablation (RFA) was the most evaluated technique, followed by microwave ablation (MWA). The local control rates of ablative therapies were generally favorable, approximately 80–90% in many studies. Representative studies demonstrated promising overall survival rates of approximately 50% or higher 5 years after ablation for lung metastases from colorectal cancer or mixed types of primary tumors. Nevertheless, the survival outcomes varied depending on the type of primary tumor and background factors of patients such as other metastases and comorbidities. Several studies had aimed to compare the outcomes of various ablative therapies such as RFA, MWA, and cryoablation; however, conclusive data are not yet available to determine the most appropriate ablation modality for lung metastases. Further data accumulation is needed, especially for long-term outcomes and comparisons with other therapies.

Percutaneous cryoablation for clinical T3a renal cell carcinoma (< 7 cm) with segmental vein involvement or perinephric fat invasion based on preoperative evaluation of high-resolution multidetector computed tomography scan

Purpose

To retrospectively assess the feasibility, safety, renal function, technique efficacy rate, and survival of patients with clinical T3a renal cell carcinoma (RCC).

Materials and methods

Sixteen cryoablation sessions were performed in 14 patients (10 men; mean age, 69.8 ± 10.5 years; range, 49–90 years) with 14 clear cell T3a RCCs (mean, 3.3 ± 0.9 cm; range, 1.9–5.2 cm). One patient was on dialysis. Transcatheter arterial embolization was performed before cryoablation in 15 sessions. The primary endpoint was the technique efficacy rate. The secondary endpoints included feasibility, safety, renal function, and survival.

Results

Cryoablation was technically successful in all RCC cases. In two RCCs, cryoablation was performed twice because of local tumor progression. No major adverse events were observed. All patients were alive without metastases, with a median follow-up of 45 months (6−93 months). Complete response was achieved by cryoablation in 11 RCCs (78.6%). The primary and secondary technique efficacy rates were 77.1% and 84.4% at 1 year, 57.9% and 73.9% at 3 years, and 57.9% and 73.9% at 5 years, respectively. One patient underwent dialysis given a total contralateral nephrectomy due to another RCC 1 month after initial cryoablation and a total ipsilateral nephrectomy 46 months after initial cryoablation due to local progression. Except for two dialysis patients, of the 12 patients with a median follow-up of 41 months (6–93 months), none were on dialysis.

Conclusion

Cryoablation was safe and effective in T3a RCC, which mainly involved the renal venous branches and may represent an alternative treatment for inoperable patients.

Correlation between renal ablation zone in contrast-enhanced CT and non-enhanced MRI during the early period following percutaneous cryoablation

Purpose

To retrospectively evaluate and correlate the contrast-enhanced computed tomography (CECT) and non-enhanced magnetic resonance imaging (MRI) during the early period following renal cryoablation.

Materials and methods

Both dynamic CECT and non-enhanced MRI were performed within 4 days following cryoablation in 34 renal tumors in 33 patients. The renal volumes of the unenhanced regions on dynamic CECT (nephrogenic phase, 4 mm thickness) and the regions with signal intensity changes on non-enhanced MRI (fat-suppressed T2-weighted image, 4 mm thickness) were evaluated. Fusion images of the axial, coronal, and sagittal sections of CECT and MRI images were created from the maximum cross-section of the renal tumor, and the match score of each image was visually evaluated on a 5-point scale.

Results

The mean renal volume of the unenhanced regions on CECT and those with signal intensity changes on non-enhanced MRI following cryoablation were 29.5 ± 19.9 cm³ (range, 4.3–97.4 cm³) and 30.7 ± 19.8 cm³ (range, 6.7–94.0 cm³), respectively; the difference between them was –1.17 cm³ (95% confidence interval [CI] –2.74, 0.40, P = 0.139). The Pearson’s product-moment correlation coefficient (r = 0.975; 95% CI, 0.951, 0.988; P < 0.0001) showed a strong correlation between the volumes. The average match score between CECT and non-enhanced MRI was as high as 4.5 ± 0.5 points (radiologist 1, 4.3 ± 0.5; radiologist 2, 4.7 ± 0.5). Local tumor control rate was 94.1% (32/34 tumors) and recurrence-free survival rate was 82.0% (95% CI: 64.2%, 91.5%) at 5 years.

Conclusions

The region with signal intensity changes on non-enhanced MRI was strongly correlated with the unenhanced region on CECT during the early period following renal cryoablation.

CT fluoroscopy-guided biopsy of pulmonary lesions contacting the interlobar fissure: An analysis of 72 biopsies

PURPOSE

The purpose of this study was to evaluate retrospectively the safety and diagnostic yield of computed tomography (CT) fluoroscopy-guided biopsy for pulmonary lesions with interlobar fissure contact.

MATERIALS AND METHODS

Seventy-two lesions showing interlobar fissure contact (mean size, 15.2 ± 5.3 [SD] mm [range: 5.3-27.0 mm]; mean length of interlobar fissure contact, 8.9 ± 3.6 [SD] mm [range: 2.6-17.5 mm] in 72 patients (33 men, 39 women; mean age, 69.7 ± 10.3 [SD] years; age range: 37-91 years) were evaluated. Multiple variables were assessed to determine the risk factors for diagnostic failure and pneumothorax. Additionally, these variables were compared between these 72 lesions and randomly selected controls (i.e., non-contact lesions).

RESULTS

All biopsies were technically successful using the transfissural (n = 14) or conventional routes (the route into the lung lobe with the target) with (n = 35) or without (n = 23) possible risk of needle insertion into the interlobar fissure after penetrating the target lesion. Sixty-eight (94.4%) procedures succeeded diagnostically and four (5.6%) failed. There were 27 grade I pneumothorax (37.5%), one (1.4%) grade II bleeding, and five (6.9%) grade IIIa pneumothorax requiring chest tube placement. Groups with and without pneumothorax did not differ significantly in patient-, lesion-, or procedure-related variables. Diagnostic yields and pneumothorax occurrence showed no significant differences between lesions with interlobar fissure contact and controls.

CONCLUSION

CT fluoroscopy-guided biopsy of pulmonary lesions with interlobar fissure contact is a safe procedure with a high diagnostic yield. Furthermore, because of potential complications, the transfissural route should be used only when a safer route is not possible.

In Vivo Microwave Ablation of Normal Swine Lung at High-power, Short-duration Settings

To evaluate the volume and heat-sink effects of microwave ablation (MWA) in the ablation zone of the normal swine lung. MWA at 100 W was performed for 1, 2, and 3 min in 7, 5, and 5 lung zones, respectively. We assessed the histopathology in the ablation zones and other outcome measures: namely, length of the longest long and short axes, sphericity, ellipsoid area, and ellipsoid volume. The mean long- and short-axis diameters were 22.0 and 14.1 mm in the 1-min ablation zone, 27.6 and 20.2 mm in the 2-min ablation zone; and 29.2 and 21.2 mm in the 3-min ablation zone, respectively. All measures, except sphericity, were significantly less with 1-min ablation than with either 2- or 3-min ablation. There were no significant differences between the 2- and 3-min ablation zones, but all measures except sphericity were larger with 3-min ablation. Although there were no blood vessels that resulted in a heat-sink effect within the ablation zones, the presence of bronchi nearby in 5 lung ablation zones resulted in reduced ablation size. In high-power, short-duration MWA, the lung ablation volume was affected by ablation time. Some ablations showed that a heat-sink effect by a neighboring bronchus might occur.

Percutaneous needle biopsy under 1.2 Tesla open MRI guidance

PURPOSE

To evaluate the feasibility of percutaneous needle biopsy using a 1.2 Tesla open magnetic resonance imaging (MRI) system, which has the highest field strength among the currently available open MRI systems.

MATERIALS AND METHODS

This single-center prospective study included 10 patients. The primary endpoint was the feasibility of biopsy needle insertion into a target lesion under 1.2 Tesla open MRI guidance. The secondary endpoints included adverse events, device failures, and success of tissue specimen acquisition. Biopsy was performed for targets in various organs using an MRI-compatible coaxial needle system consisting of a 16G introducer needle and 18G semi-automatic biopsy needle. A newly developed body coil with a suitable design for intervention was used for intraprocedural imaging.

RESULTS

Biopsy procedures were performed for six musculoskeletal masses, two retroperitoneal masses, one renal mass, and one liver mass. The median diameter of the targets was 4.9 cm (range 2.1-22.8 cm). MRI-guided biopsy needle insertion was feasible in all 10 patients. In total, four grade 1 adverse events (as per Common Terminology Criteria for Adverse Events version 4.0) occurred in three patients. Adequate biopsy specimens for pathological diagnosis were successfully obtained from all 10 patients.

CONCLUSION

Percutaneous needle biopsy using a 1.2 Tesla open MRI system was feasible for relatively large targets, especially in the musculoskeletal region.

Computed Tomography-guided Core Needle Biopsy for Renal Tumors: A Review

Small renal tumors are sometimes challenging to diagnose accurately through imaging alone, and image-guided biopsies are performed when histological diagnoses are needed. Although ultrasound guidance is usually chosen for renal tumor biopsies, computed tomography guidance is preferred for selected cases; e.g., obese patients or when the target is undetectable by ultrasound (as those in the upper pole). In the 14 recently published studies covering ≥50 procedures, computed tomography-guided renal tumor biopsies had a wide range diagnostic yield (67.4%-97.4%). Complications often occurred; however, most were minor and asymptomatic. No biopsy-related deaths and tumor seeding occurred. This study aimed to review the advantages and disadvantages, procedure techniques, diagnostic yields, and complications of core needle biopsies for renal tumors under computed tomography guidance.

Percutaneous Cryoablation of Lower Limb Soft-Tissue Venous Malformations: Preliminary Results of Long-Term Efficacy

PURPOSE

To retrospectively evaluate long-term efficacy of percutaneous cryoablation for lower limb soft-tissue venous malformations.

MATERIALS AND METHODS

Nine patients (mean age, 36.6 years) with lower limb soft-tissue venous malformations were included. Cryoablation was performed percutaneously using an argon-based system. Adverse events (AE) using the Common Terminology Criteria for AEs version 4.0 were evaluated. The visual analog scale (VAS) scores and lesion volumes measured on magnetic resonance imaging were also evaluated at 12 months and 5-6 years.

RESULTS

Technical success (i.e., complete coverage of the lesion by an iceball) was achieved in eight of the nine patients. All patients developed a total of 14 grade 1 or 2 adverse events. The mean (± standard deviation) VAS score was 6.0 (± 1.7) before therapy, whereas it was 0.14 (± 0.27) at 12 months and 0.97 (± 1.3) at 5-6 years (58-78 months). Complete pain relief was obtained in 6 and 5 patients at 12 months and 5-6 years, respectively. The median lesion volume was 2.49 mL before therapy, whereas it was 0.26 mL at 12 months and 0.35 mL at 5-6 years.

CONCLUSION

Percutaneous cryoablation of lower limb soft-tissue venous malformations achieved considerable pain relief and lesion shrinkage for 5-6 years in this small preliminary study.

LEVEL OF EVIDENCE

Level 4, Case Series.

CT-guided biopsy of lung nodules with pleural contact: Comparison of two puncture routes

PURPOSE

The purpose of this study was to retrospectively compare two puncture routes (transpleural vs. transpulmonary) for computed tomography (CT) fluoroscopy-guided cutting needle biopsy of lung nodules with pleural contact.

PATIENTS AND METHODS

A total of 102 patients (72 men; mean age, 71.1±9.5 [SD] years) were included and 102 biopsies of 102 lung nodules (mean size, 16.7±5.9 [SD] mm; range, 6.0-29.4mm; mean length of pleural contact, 10.1±4.2 [SD] mm; range, 2.8-19.6mm) were analyzed. All procedures were classified as biopsies via the direct transpleural route or the transpulmonary route. The patient-, lesion-, and biopsy-related variables, diagnostic yields, and incidence of complications were compared between the two routes.

RESULTS

Biopsy was performed via the direct transpleural route (n=59; 57.8%) and transpulmonary route (n=43; 42.2%). In the transpulmonary route group, the mean distance of the intrapulmonary pathway was 17.7±9.4 [SD] mm (range: 4.1-47.6mm; P<0.001) and the introducer needle trajectory angle of<45° was significantly observed (8.5% [5/59] vs. 60.5% [26/43]; P<0.001). There was no significant difference in diagnostic accuracy between the direct transpleural and transpulmonary routes (93.2% [55/59] vs. 90.7% [39/43]; P=0.718). The frequencies of all complications (64.4% [38/59] vs. 97.7% [42/43]; P<0.001), pneumothorax (33.9% [20/59] vs. 65.1% [28/43]; P=0.003), pneumothorax with chest tube placement (3.4% [2/59] vs. 18.6% [8/43]; P=0.016), and pulmonary hemorrhage (47.5% [28/59] vs. 76.7% [33/43]; P=0.004) were significantly lower in the direct transpleural group.

CONCLUSION

Direct transpleural route is recommended for CT fluoroscopy-guided biopsy of lung nodules with pleural contact because it is safer and yields similar diagnostic accuracy than transpulmonary route.

Follow-up with serum IgG4-monitoring in 8 patients with IgG4-related disease diagnosed by a lacrimal gland mass

The diagnostic criteria for IgG4-related disease were previously published and serum IgG4 measurement has been reimbursed by national health insurance in Japan since 2012. Eight patients diagnosed with IgG4-related disease based on lacrimal gland masses were retrospectively reviewed. The 8 patients were 3 men and 5 women ranging in age from 52 to 77 (median, 63) years at the initial visit and their follow-up period ranged from 0.25 to 11 (median, 7) years. Bilateral and unilateral involvement were noted in 4 patients each; 2 on the right side and 2 on the left side in those with unilateral involvement. Serum IgG4 was high in 5 of 8 patients at the initial visit. Five patients with no systemic signs were followed without treatment, whereas oral steroids were administered and tapered in the other 3 patients who exhibited systemic signs. One patient with a history of radiation for MALT lymphoma in bilateral lacrimal glands developed IgG4-related disease in the left lacrimal gland 10 years later and was followed without treatment. Nine years later, her serum IgG4 level increased to 1500 mg/dL and paracardiac lesions, found on positron emission tomography, were confirmed to be MALT lymphoma by needle biopsy, leading to systemic chemotherapy. The other 7 patients had neither local recurrence nor additional systemic signs. Serum IgG4 monitoring may be useful to detect systemic complications in IgG4-related ophthalmic disease and markedly high serum IgG4 levels may indicate new lymphoma at other sites.

Contrast examination of central venous access port implanted through internal jugular vein for evaluation of suspected complications

PURPOSE

We summarized the findings, diagnosis, and outcomes of cases for which contrast examination of central venous access ports (CV-ports) were attempted to detect complications.

MATERIALS AND METHODS

Fifty-seven contrast examinations were attempted for 45 patients with 46 CV-ports (median, 162 days after implantation). Contrast examination was performed due to three suspicion catheter fractures or 54 CV-port dysfunctions (combinations of an absence of blood reflux on aspiration and 9 sufficient, 21 insufficient, or 24 impossible drip infusions).

RESULTS

Contrast examination was successfully performed in 52 cases and revealed 45 normal findings, 5 pericatheter fibrin sheath formations, and 2 partial catheter fractures. In 23 of 45 cases with normal findings, the resistance to injection was initially mild or moderate but resolved after the CV-port was flushed slowly with heparinized saline solution. Subsequent contrast examination demonstrated normal findings. All fibrin sheath formations disappeared after thrombolytic therapy. Five cases could not undergo contrast examination due to high resistance. After contrast examination, nine of 46 CV-ports were removed or exchanged, while the use of the remaining 37 continued.

CONCLUSION

Contrast examination of CV-port allowed the assessment of suspected complications and early treatment.

Needle artifact characteristics and insertion accuracy using a 1.2T open MRI scanner: A phantom study

PURPOSE

To evaluate the characteristics of needle artifacts and the accuracy of needle insertion using a 1.2 Tesla open magnetic resonance imaging (MRI) system in a phantom.

MATERIALS AND METHODS

First, the apparent width of the needle on the MRI and the needle tip position error of 16- and 18-gauge MRI-compatible introducer needles and a 17-gauge cryoneedle were examined with different needle angles (0°, 30°, 45°, 60°, and 90°) to the main magnetic field (B0), sequence types (balanced steady-state acquisition with rewound gradient echo [BASG] and T2-weighted fast spin echo [FSE] sequence), and frequency encoding directions. Second, the accuracy of needle insertion was evaluated after 10 MRI fluoroscopy-guided insertions in a phantom.

RESULTS

The apparent needle widths was larger when the angle of the needle axis relative to B0 was larger. The needles appeared larger on BASG than on T2-weighted FSE images, with the largest apparent widths of 16-, 17-, and 18-gauge needles of 14.3, 11.6, and 11.0mm, respectively. The apparent needle tip position was always more distal than the actual position on BASG images, with the largest longitudinal error of 4.0mm. Meanwhile, the 16- and 18-gauge needle tips appeared more proximal on T2-weighted FSE images with right-to-left frequency encoding direction. The mean accuracy of MRI fluoroscopy-guided needle insertion was 3.1mm.

CONCLUSION

These experiments clarify the characteristics of needle artifacts in a 1.2 Tesla open MRI. With this system, the MRI fluoroscopy-guided needle insertion demonstrated an acceptable accuracy for clinical use.

Hemobilia after bile duct resection: perforation of pseudoaneurysm into intra-pancreatic remnant bile duct: a case report

BACKGROUND

Hemobilia occurs mainly due to iatrogenic factors such as impairment of the right hepatic or cystic artery, and/or common bile duct in hepatobiliary-pancreatic surgery. However, little or no cases with hemobilia from the intra-pancreatic remnant bile duct after bile duct resection (BDR) has been reported. Here, we report a case of massive hemobilia due to the perforation of psuedoaneurysm of the gastroduodenal artery (GDA) to the intra-pancreatic remnant bile duct after hepatectomy with BDR.

CASE PRESENTATION

A 68-year-old male underwent extended right hepatectomy with BDR for gallbladder carcinoma. He presented with upper gastrointestinal bleeding 2 months after the initial surgery. Upper endoscopy identified a blood clot from the ampulla of Vater and simultaneous endoscopic balloon tamponade contributed to temporary hemostasis. Abdominal CT and angiography revealed a perforation of the psuedoaneurysm of the GDA to the intra-pancreatic remnant bile duct resulting in massive hemobilia. Subsequent selective embolization of the pseudoaneurysm with micro-coils could achieve complete hemostasis. He survived without any recurrence of cancer and bleeding.

CONCLUSION

Hemobilia could occur in a patient with BDR due to perforation of the pseudoaneurysm derived from the GDA to the intra-pancreatic remnant bile duct. Endoscopic balloon tamponade was useful for a temporal hemostasis and a subsequent radiologic interventional approach.

Oncologic outcomes and safety of percutaneous cryoablation for biopsy-proven renal cell carcinoma up to 4 cm in diameter: a prospective observational study

BACKGROUND

Percutaneous cryoablation is widely used for the treatment of renal cell carcinoma. We prospectively evaluated the oncologic outcomes and safety of percutaneous cryoablation for the treatment of tumors ≤ 4 cm in diameter.

METHODS

We included patients aged ≥ 20 years, who had histologically proven renal cell carcinoma, tumor diameter ≤ 4 cm, a performance status of ≤ 1, acceptable laboratory parameters, were inoperable or refused to undergo surgery, and had signed a written informed consent. The primary endpoint was the cause-specific survival rate. The secondary endpoints were overall and progression-free survival, and adverse event frequency and grade. All procedures were percutaneously performed under computed tomography fluoroscopy guidance.

RESULTS

From October 2013 to October 2015, 33 patients (mean age: 68 ± 14 years; sex: six women, 27 men) were enrolled. The mean tumor diameter was 2.1 ± 0.6 (range 1.0-3.4) cm. The median follow-up period was 60.1 (range 18.4-76.6) months. One patient died of non-renal cell carcinoma-related disease 46 months after percutaneous cryoablation. The cause-specific and overall survival rates were 100% and 96.8% at 3 years, and 100% and 96.8% at 5 years, respectively. There was no local tumor progression or distant metastasis. The incidence of severe urological (urinary fistula and perinephric infection) and non-urological adverse events (increased creatine kinase and skin ulceration) was 6% each.

CONCLUSION

Percutaneous cryoablation for renal cell carcinoma ≤ 4 cm in diameter achieved good tumor control with a low complication frequency.

Combined Laparoscopic and CT Monitoring of the Ice-Ball Margin during Cryoablation for Renal Cell Carcinoma Associated with von Hippel-Lindau Disease: First Case

We report a 47-year-old Japanese female with 10 previous treatments for multiple bilateral renal cell carcinoma (RCC) associated with von Hippel-Lindau disease. The 14-mm right lower pole renal tumor was in contact with the right ureter. Laparoscopic cryoablation was performed to protect the ureter wrapped with gauze. Computed tomography (CT) monitoring was used to confirm the precise ≥ 6 mm ice-ball margin. There was no local progression at 6-months post-surgery. The serum creatinine has been stable. This is apparently the first report of combined laparoscopic and CT monitoring of an ice-ball formation and its margin during cryoablation for RCC.

A Clinical Study Evaluating an Aspiration-type Semi-Automatic Cutting Biopsy Needle (SCIRO-1702)

An aspiration-type semi-automatic cutting biopsy needle enables tissue cutting during application of negative pressure, which is expected to contribute to a larger amount of specimen. The aim of the present study was to evaluate this novel needle in a clinical setting. Patients who underwent image-guided percutaneous biopsy for lung or renal masses were enrolled. Cutting biopsy was performed with and without aspiration during each procedure. The specimens were weighed using an electronic scale. The weights were compared between specimens obtained with and without aspiration using a paired t-test. The data from 45 lung and 30 renal biopsy procedures were analyzed. In lung biopsy, the mean±standard deviation weights of specimens obtained with and without aspiration were 2.20±1.05 mg and 2.24±1.08 mg, respectively. In renal biopsy, the mean weights were 6.52±2.18 mg and 6.42±1.62 mg, respectively. The weights were not significantly different between specimens obtained with and without aspiration either in lung (p=0.799) or renal (p=0.789) biopsies. The application of negative pressure with the aspiration-type semi-automatic cutting biopsy needle did not contribute to an increase in the amount of the specimen obtained in lung and renal biopsies.

Difference in specimen weights with semi-automatic cutting biopsy needles

PURPOSE

To assess specimen weight difference of six types of semi-automatic cutting biopsy needles.

MATERIALS AND METHODS

We compared 18- and 20-gauge needles, one aspiration-type (STARCUT^® aspiration-type, TSK Laboratory, Tochigi, Japan) and five non-aspiration-type (MISSION^®, BARD, AZ; SuperCore™, Argon Medical Devices, TX; Temno Evolution^®, Care Fusion, IL; FINE CORE^®, Toray Medical, Tokyo, Japan; Quick-Core^®, Cook, IN) needles. Four biopsies were performed with each needle with the longest throw length on an excised bovine liver. The biopsies were repeated with new needles, four times with four different livers. STARCUT^® was used both with and without aspiration.

RESULTS

Sixteen specimens were obtained with each needle. In needles of gauges, STARCUT^® with aspiration provided the heaviest specimen and significantly heavier specimens were obtained with STARCUT^® with aspiration (P < 0.05) than five non-aspiration-type needles. The specimen weight differed significantly (P < 0.001) among all 18- and 20-gauge needles. The specimen weights did not differ significantly between aspiration and non-aspiration biopsies with STARCUT^® (6.32 vs. 5.97 mg with 18-gauge needle, P = 0.342; 1.95 vs. 1.92 mg with 20-gauge needle, P = 0.886).

CONCLUSION

Although STARCUT^® with aspiration provided the heaviest specimen, specimen weights were not significantly different between aspiration and non-aspiration biopsies. We assessed the specimen weight difference of six types of semi-automatic cutting biopsy needles. Significantly heavier specimens were obtained with STARCUT^® with aspiration than the other needles. The specimen weight differed significantly among all 18- and 20-gauge needles but did not differ significantly between aspiration and non-aspiration biopsies with STARCUT^®.

Computed tomography fluoroscopy-guided cutting needle biopsy of pulmonary nodules ≤8 mm: A retrospective study including 117 nodules

PURPOSE

To evaluate the diagnostic yield and safety of computed tomography (CT) fluoroscopy-guided cutting needle biopsy (CNB) for pulmonary nodules ≤ 8 mm.

METHOD

Data of CT fluoroscopy-guided CNB for pulmonary nodules ≤ 8 mm performed in a single institution were retrospectively analyzed. One hundred and seventeen biopsy procedures for 117 pulmonary nodules (mean size, 7.4 mm) in 114 patients were included in the study. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated. Univariate analyses were performed to elucidate the risk factors for diagnostic failure (i.e., non-diagnostic, false-positive, or false-negative results). Complications were graded per the Clavien-Dindo Classification.

RESULTS

One (0.9 %) non-diagnostic biopsy result was found. The diagnostic accuracy was 95.7 % (112/117). The sensitivity and specificity were 95.8 % (91/95) and 95.5 % (21/22), respectively. PPV and NPV were 98.9 % (91/92) and 87.5 % (21/24), respectively. Univariate analyses showed that nodules in the lower lobes (p = 0.006) and prone biopsy position (p = 0.021) were the significant risk factors for diagnostic failure. The incidence of pneumothorax requiring chest tube placement (Grade IIIa) was 6.8 % (8/117). No Grade IIIb or higher complications were observed.

CONCLUSION

CT fluoroscopy-guided CNB for pulmonary nodules ≤ 8 mm showed a high diagnostic yield without severe complications.

Radiofrequency Ablation for Stage I Non-Small Cell Lung Cancer: An Updated Review of Literature from the Last Decade

This review summarizes the current findings on radiofrequency ablation (RFA) for stage I non-small cell lung cancer (NSCLC) from relevant literature published in the last decade. While most earlier studies included small populations and had short follow-up periods, more robust data have become available owing to prospective or large cohort studies. The reported overall survival rates after RFA for stage I NSCLC were 83-96%, 40-74%, and 23-61% at 1, 3, and 5 years, respectively, in recent studies. Furthermore, many comparative studies on the outcomes of RFA and stereotactic body radiotherapy have been performed. Most of these studies report no significant difference in survival outcomes between the therapies. Currently, major guidelines define RFA as a reasonable alternative treatment for stage I NSCLC in non-surgical candidates.

Recurring Local Tumor Progression After Cryoablation of Renal Cell Carcinoma

We describe three cases of renal cell carcinoma (RCC) with recurring local tumor progression, i.e., local failure following repeat cryoablation for a locally progressed tumor. A second local progression developed in all cases after cryoablation for the first local progression, despite there being a sufficiently large ice-ball margin. In two cases, the second local progression was treated with microwave ablation and controlled in the follow-up. In one case, a third cryoablation was performed, but a third local progression developed after 12 months. These cases suggest that some RCCs may be refractory to cryoablation. In cases of recurring local progression, switching from cryoablation to another ablation modality may be an alternative.

Computed Tomography Fluoroscopy-guided Core Needle Biopsy of Abdominal Para-aortic Lesions: A Retrospective Evaluation of the Diagnostic Yield and Safety

Purpose:

Material and Methods:

Results:

Conclusions:

MRI-guided percutaneous needle biopsy with 1.2T open MRI: study protocol for a prospective feasibility study (SCIRO-1701)

There has been growing interest in magnetic resonance imaging (MRI)-guided interventional procedures such as percutaneous needle biopsy. Although open MRI is preferable for MRI-guided procedures in terms of patient accessibility, its inferior imaging capability due to lower field strength is a substantial limitation. In this situation, the high-field (1.2T) open MRI has recently become available. This novel MRI system is expected to provide excellent image quality as well as good patient accessibility, potentially contributing to safe and accurate device manipulation. This trial is designed to investigate the feasibility of MRI-guided percutaneous needle biopsy with this system. Patients with lesions needing percutaneous needle biopsy for pathological diagnosis are included. The enrollment of ten patients is intended. The primary endpoint of this study is the feasibility of biopsy needle insertion under real-time MR-fluoroscopy guidance based on the presence of the notch of the biopsy needle within the target lesion. The secondary endpoints are adverse events, device failures, and success of specimen acquisition. Once the feasibility of MRI-guided biopsy with 1.2T open MRI is validated by this study, it may potentially encourage widespread use of MRI-guidance for biopsy procedures. Furthermore, it may lead to development of the other MRI-guided interventional procedures using this MRI system.

Robotic needle insertion during computed tomography fluoroscopy-guided biopsy: prospective first-in-human feasibility trial

INTRODUCTION

This was a prospective, first-in-human trial to evaluate the feasibility and safety of insertion of biopsy introducer needles with our robot during CT fluoroscopy-guided biopsy in humans.

MATERIALS AND METHODS

Eligible patients were adults with a lesion ≥ 10 mm in an extremity or the trunk requiring pathological diagnosis with CT fluoroscopy-guided biopsy. Patients in whom at-risk structures were located within 10 mm of the scheduled needle tract were excluded. Ten patients (4 females and 6 males; mean [range] age, 72 [52-87] years) with lesions (mean [range] maximum diameter, 28 [14-52] mm) in the kidney (n = 4), lung (n = 3), mediastinum (n = 1), adrenal gland (n = 1), and muscle (n = 1) were enrolled. The biopsy procedure involved robotic insertion of a biopsy introducer needle followed by manual acquisition of specimens using a biopsy needle. The patients were followed up for 14 days. Feasibility was defined as the distance of ≤ 10 mm between needle tip after insertion and the nearest lesion edge on the CT fluoroscopic images. The safety of robotic insertion was evaluated on the basis of machine-related troubles and adverse events according to the Clavien-Dindo classification.

RESULTS

Robotic insertion of the introducer needle was feasible in all patients, enabling pathological diagnosis. There was no machine-related trouble. A total of 11 adverse events occurred in 8 patients, including 10 grade I events and 1 grade IIIa event.

CONCLUSION

Insertion of biopsy introducer needles with our robot was feasible at several locations in the human body.

KEY POINTS

• Insertion of biopsy introducer needles with our robot during CT fluoroscopy-guided biopsy was feasible at several locations in the human body.

Usefulness of a CT-guided hookwire marking in laparoscopic partial hepatectomy for hepatocellular carcinoma invisible on ultrasonography

INTRODUCTION

The intra-operative detection of hepatocellular carcinoma (HCC) by ultrasonography is indispensable for laparoscopic partial hepatectomy. However, it is occasionally difficult to localize an HCC on an ultrasound in chronic liver disease. Two cases of partial hepatectomy using hookwire marking under CT guidance are presented.

MATERIALS AND SURGICAL TECHNIQUE

The location of the HCC was identified by CT scan, and the puncture site was determined. A hookwire system, made of a stainless steel hook, was used to localize the HCC. The hookwire was placed percutaneously close to the HCC, and then the patient was taken to the operating room as soon as possible. After identification of the hookwire marker, the cutting line was determined on the liver surface to ensure a sufficient surgical margin in laparoscopic partial hepatectomy.

DISCUSSION

Two cases underwent these procedures with easy intra-operative marking of the resection area. This technique facilitates safe laparoscopic partial hepatectomy for an HCC that is invisible on ultrasound.

Lung cancer ablation: complications

Although radiofrequency ablation for lung cancer is generally safe (with a mortality rate <1%), it may cause various complications. Common complications include pneumothorax, pleural effusion, and parenchymal hemorrhage. Although most complications can be treated conservatively or with minimal therapy, physicians should be aware of rare but serious complications. Potentially fatal complications include massive hemorrhage, intractable pneumothorax due to bronchopleural fistula, pulmonary artery pseudoaneurysm, systemic air embolism, and pneumonitis. Other serious complications include injury to the nearby tissues (e.g., brachial nerve plexus, phrenic nerve, diaphragm, and chest wall), needle tract seeding, lung abscess, empyema, and skin burn. Although cavitation of the ablation zone is usually insignificant clinically, such a cavity occasionally ruptures, leading to pneumothorax and bleeding. Cavities may also serve as a scaffold for fungal colonization. Precautions to minimize risk should be taken whenever possible. Nevertheless, serious complications may occur, and thus physicians should be aware of the appropriate treatments for these complications. This article reviews complications associated with lung cancer ablation.

Sarcoid-like lung granulomas in a hemodialysis patient treated with a dipeptidyl peptidase-4 inhibitor

It has been reported that the inhibition of dipeptidyl peptidase-4 (DPP-4)/CD26 on T-cells by DPP-4 enzymatic inhibitors suppresses lymphocyte proliferation and reduces the production of various cytokines, including tumor necrosis factor (TNF)-α. A 72-year-old female with diabetic nephropathy on hemodialysis developed multiple lung nodules following the administration of vildagliptin. A biopsy demonstrated the histology of granulomas without caseous necrosis. The discontinuation of vildagliptin resulted in the disappearance of the granulomas within 4 months. As granulomatosis often develops in patients under anti-TNF-α therapy, the accumulation of DPP-4 inhibitors or its metabolites is possibly linked to unrecognized complications, such as sarcoid-like lung granulomas.